Values still wouldn't work. You'd have to change their types to `() -> whatever` and that means a lot of churn.

Even strict-by-default languages that let you easily make values explicitly lazy would mean type level churn, if not term level.

The value part is important because it means you can't really talk about partially implemented hypothetical results where you know how to handle one branch of a function, but not another. This is a super common divide-and-conquer technique in Haskell.

Could possibly half-ass it if you have some kind of panic functionality, but it'll fail unconditionally in a strict language when the result of the function is forced. In Haskell, if you don't use the bottom, it doesn't blow up.